I did two Corona projects to keep me busy during the lockdowns.
The first one was a music streamer based on a Raspberry Pi 4, DAC and stable DC power supply.https://www.audiophonics.fr/en/dac-and-interfaces-for-raspberry-pi/audiophonics-dac-i-sabre-es9038q2m-raspberry-pi-i2s-spdif-pcm-dsd-usb-c-power-supply-p-12795.htmlhttps://www.amb.org/audio/sigma11/
I played a bit with RuneAudio and Volumio, the latter won for personal preferences.
My audio equipment consists of a Cambridge Works surround sound system and a Pioneer https://www.amb.org/audio/sigma11/
. All quite old.
This is fine for watching movies but not for listening to music.
So, the journey started for a set of speakers.
I read a lot of reviews about many speaker systems. But what caught my attention was Mr. Richie's, from GR Research, explanation about value for money when buying of the shelve speakers.
One caveat is that you cannot go to a shop and listen to his speakers. At least not in Belgium. It took some time to decide between the X-LS Encore and X-MTM.
Why the X-MTM? Because with the X-LS's you need to buy stands to put them to listening height. The X-MTM's are at the perfect listening height. And stands don't come for free.
During my 'research', I watched a lot of reviews from the following people:
Steve Guttenberg Audiophiliac - https://www.youtube.com/channel/UC9wBmplRUhaCi-aNrkfgeTg
New Record Day - https://www.youtube.com/user/NewRecordDay
And of course GR-Research - https://www.youtube.com/channel/UCIJHwsTJyrH4YznoJxZmJHQ
The enthusiasm, knowledge they show is phenomenal. Although YouTube cannot provide the sound quality to decide on differences between different equipment, the explanations these people provide set you on the right track.
Before I start explaining the build, let me tell you everything you read about the quality of GR Research does not do justice to the reality, it is amazing.Mr. Richie replies prompt to your questions. The kit contains everything, from OFC copper wire for the internal wiring, to solder, to plans for building the filters. Don't forget to order norezz. And the sound quality, ...
The sound quality is something I cannot describe. The first time I started listening to these speakers was an emotional moment. When I closed my eyes, I was at a live concert. I now understand what the audiophiles mean with sound stage. And the speakers still must be broken in.
Lucky for me, I've done my research, the DAC in the music streamer is able to handle SACD's and high resolution FLAC. Whether the Pioneer is handling these tracks in a decent way is still an open question. Maybe a third Corona project.
If you have the skills, know somebody to help, do not hesitate to put a kit from GR Research together. You will be surprised by the quality and the satisfaction to be able to say that you put it together yourself. Just take the time.
The music I listened to was what Steve Guttenberg recommends:https://www.youtube.com/watch?v=8omBalTE1Do&t=259s
And Pink Floyd, Al Stewart, Steely Dan, Edith Piaf, ZZ Top, Kraftwerk, and many others.
Selection of the material for the cabinets. Since I live in Belgium, getting a flat pack from the US is really expensive. I needed to source that locally. But what material? MDF? Plywood? This review made me decide on plywood:https://www.youtube.com/watch?v=EEh01PX-q9I&t=2852s
I bought two sheets of Lauan plywood. The density is about 500 Kg per cubic meter. MDF is about 750 Kg.
The shop has a service to cut the plywood sheets in strips 4 mm wider than the required sizes for front, back, sides, braces, …
These strips where cut to length in my basement.
Strips cut to length:
Routing grooves for the braces:
The braces (lots of them):
Cutting the front panels:
The filters (thanks Danny for your instructions video):
Putting the pieces together:
Filling, sanding, painting, filling, sanding, painting, filling, sanding, painting,... 3 layers of primer, 4 layers of high gloss white paint:
Details of the bottom (feet and dampers are screwed on with M8 bolts in threaded inserts, cut to length to 12 mm to not travers the plywood):
Tube connectors in the black&white theme:
The felt on the dampers allows me to slide the speakers around. I change sitting position quite regularly.
I hope that this story inspires others.
There will be a third Corona project. And that is a new amplifier.
I'm very sensitive to listening fatigue, exaggerated lows and highs put me of after 15 minutes. These speakers are perfectly balanced.
The biggest question is to go for tubes or solid state.
I have kind of set my heart on the Gato AMP 150 (what a design and excellent reviews). The McIntosH MA5300 (but I don't need a DAC) could be an alternative.
Tubes, Elekit TU-8600, …